Most vehicles today, particularly most passenger vehicles, utilize disk brake arrangements for braking. Of these, almost all disk brake arrangements have so-called floating caliper disc brakes. The caliper of the floating caliper disc brake is movably mounted on a yoke or bracket that is fixed to the axle housing. According to this arrangement, the floating caliper can slide in a direction that is parallel with the long axis of the brake rotor. The brake caliper retains a pair of spaced apart and opposed pads that are placed on either side of the brake rotor. A movable piston is provided in the brake caliper and in operative association with one of the brake pads.
The brake caliper is provided with a pair of spaced apart guide pins that pass through corresponding apertures formed in ears provided on the yoke. In this way the pins secure the brake caliper to the yoke. The floating brake caliper has an advantage over non-floating brake calipers in that it is durable and can readily self-adjust to take up wear on the brake pads over time in vehicle operation. The components of the brake assembly can also be formed from lightweight and low cost materials.
Because the brake pads wear over time, it is desirable to provide a brake pad wear sensing system that transmits the information to the vehicle operator. While it is known for the vehicle operator to feel and, in some instances, hear worn brake pads based on grooves formed in the face of the pad, more recent wear sensors are provided that electronically sense brake pad wear. Traditional electronic wear sensors used wires and connectors which connect the brake pad sensors to an electronic module on the vehicle. These wired sensors require long wiring runs and flexible connections to the wheel ends making them expensive and prone to damage.
In response, wireless wear sensors are offered on some vehicles. This is possible because wireless wear sensors are becoming less expensive and avoid many of these failure modes. Wireless components associated with brake systems require batteries for operation. However, while a simple concept, in execution the idea of batter-operated wireless components are challenged by environmental factors such as vehicle-generated heat. Accordingly, batteries on wireless components, such as brake wear sensors, must be kept cool. Otherwise, the batteries rapidly degrade and lose transmission capability. Finding an acceptable location for a transmitter in relation to a wheel end environment is particularly difficult because of the heat generated by the brake and by the bearing inside the wheel.
There is thus a demand in the industry for an improved system of wireless transmission of brake pad condition. Adding to this demand is the autonomous vehicles which isolate the passenger's ability to feel a vehicles dynamic performance. Without this connectivity, it may not be possible for vehicle owners to feel when their brakes are worn out and their vehicle needs maintenance. Reacting to this, there is a growing need to have electronic brake pad sensors installed onto vehicles.
Thus a new approach to the pendulum bumpers is needed to address the problems associated with known arrangements.